Comparative Reliability Analysis of Milling Teeth Manufactured by Conventional Cutting Processes and Laser Cladding

This paper presents the estimation of the main reliability indices of two milling teeth types. The comparative analysis referred to milling teeth manufactured by conventional cutting processes, made of 41Cr4 (type I), and milling teeth manufactured by high-productivity welding loading processes, namely, laser cladding (type II). To analyze the distributions of the lifetime data specific to milling teeth types, the correlation coefficient value was considered. Goodness-of-fit analysis indicated that normal distribution was adopted in order to conduct parametric estimates of the reliability indices. Point estimations of the parameters and estimations with 95% confidence intervals of the components' lifetimes were performed, applying the least squares estimation method. Compared to the type II milling teeth, lower values of the reliability function were estimated for the type I milling teeth. The type II milling teeth displayed higher values for the statistical parameters, with a mean of 6 h, while the mean of the failure of the type I milling teeth was 5.2 h. In addition, a more pronounced hazard rate for the type I milling teeth compared to the type II milling teeth was observed.